BURNS -- The FBI has staged at the Burns Municipal Airport, blocking entrance to a U.S. Bureau of Land Management base there used to fight fires during the summer.

Men in FBI gear were posted Saturday in a sport utility vehicle along Airport Road about five miles east of the city, keeping cars and trucks from entering a BLM "SEAT Base" where another large vehicle sat equipped with FBI signage, numerous antennae, a satellite dish and other gear.

The men declined to answer questions or identify themselves and asked a reporter not to enter the SEAT Base on foot. SEAT stands for "single engine air tanker," a small agricultural airplane used to drop fire retardant on wildfires. Law enforcement officials have been posted there for days.

The FBI's presence was another reminder of the armed occupation more than 30 miles away at the Malheur National Wildlife Refuge, which entered its eighth day Saturday. A group of militants led by Arizona businessman Ammon Bundy and joined Friday by an armed group of self-styled patriots from Idaho has commandeered the bird sanctuary to protest the federal government's ownership of public land in Harney County.

Bundy, son of Nevada rancher Cliven Bundy, has refused to leave the refuge despite public entreaties by residents and Sheriff Dave Ward's offer to peacefully escort the militants out of town. On Saturday, about two dozen new arrivals showed up with rifles and bulletproof vests.

Jeff Cotton, manager at the city-owned airport, said the BLM operates the SEAT Base as a separate entity. The Burns Municipal Airport remains open, he said. Cotton confirmed that the FBI was staged at the SEAT Base but said he didn't know what officials were doing there.

There was no sign of federal law enforcement at the BLM's Burns headquarters in nearby Hines. For the militants, the BLM is one of the main symbols of what they see as the federal government's overreach.

About six or seven planes are in hangars at the airport, Cotton said, with about six more stationed outside. There's no air traffic control tower, he said - pilots simply announce when they're coming to the airport.